1. Field of the Invention
The invention relates to the field of epitaxial growth of hexagonal ferrites on spinel substrates.
2. Prior Art
Liquid phase epitaxial growth has become well established as a general technique for growing thin films of desired materials on monocrystalline substrates. The melt composition generally comprises a flux such as barium oxide/boron oxide or lead oxide/boron oxide. To this flux are added source compounds which contain the component ions of the film to be grown. The source compounds are usually oxides or compounds which will decompose to oxides at the high temperature to which the melt is heated in order to form a uniform melt prior to film growth. The source compounds are usually included in the melt in quantities which provide a stoichiometric quantity of each of the ions present in the film to be grown. The flux and source materials are usually mixed as powders and heated to a high enough temperature that they melt and may be stirred to form a homogeneous melt. The melt is then cooled to below its saturation temperature with respect to the deposition of the desired film material. A substrate on which it is desired to deposit the film is lowered into the melt for a period of time sufficient to grow the desired film to the desired thickness.
Composites of M-type or W-type hexagonal ferrite thin films on nonmagnetic substrates would be useful because of the microwave properties of these hexagonal ferrites. Unfortunately, prior art attempts to grow such films by liquid phase epitaxy on non-magnetic substrates have proved unsuccessful.
A method is needed which will successfully grow M-type and W-type hexagonal ferrites on non-magnetic substrates.